Fin Rot?!? Red spots and a tear in my guppy's tail!?

Question

I isolated my guppy in a little 1 gal this morning to nurse him back to health a little because he was not able to get at the food in my 10 gal. I used the water from my established tank. But there is no filter or heater. I just treated him for a parasite and now he has these red spots on his tail and a what looks like a tear in the middle. Is this fin rot now?!?? How do I treat this?!?!??

How long can I keep him in this 1 gal with no heater and no filter?

Answer 1

your guppy has fin rot. you can keep him in the 1 gal as long as you need, just do water changes every so often. he probably caught it from another fish in your tank. the last thing you want to do is heat his tank. that just speeds up the process. if you can keep him isolated in cooler water it may eventually heal but thats definitely not a 100% chance of working.  its good you used medication.  you know thats there no hope once the tail is totally gone or just a little stub. good luck with your guppy. : )

Answer 2

Parasite medication will have no effect on bacterial fin rot.  Instead, remove any activated carbon from the filter and start treating with Maracyn 2, Maracyn TC, Furan 2, Triple Sulfa, Trisulfa, Kanaplex, or similar gram negative effective medications.  I would also suggest getting some kind of aerating device, whether it's a small filter or an air stone.

EDIT: This is a separate bacterial infection.  It is possible that the stress from the parasite allowed the bacterial infection to get a foot hold, but it is not directly related.  Flimsy, transparent/white fin edges and red spotting are generally caused by a combination of fin rot and septicemia (a blood infection), both of which will be easily treated with any of the above medications.